US1596394A

US1596394A - Testing jig and method of use

Info

Publication number: US1596394A
Application number: US617491A
Authority: US
Inventors: Carl F Braun
Original assignee: Individual
Current assignee: Individual
Priority date: 1923-02-07
Filing date: 1923-02-07
Publication date: 1926-08-17
Anticipated expiration: 1943-08-17

Description

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Patented Aug. 17, 1926.

1,596,394 PATENT orifice.

CARL F. BRAUN, OF PASADENA, CALIFORNIA.

TESTING Jie AND METHOD or Usn.

Application led `February rlhis invention relates toa method and means of testing the tubes of tubular apparatus, such as heat exchangers, condensers, tubular boilers, and the like. Y

1t often occurs that a tubein'a heat exchanger or like'structure develops a leak,

when lthe floating head of the tube nest isv lower than the other. In that eventl fluid from a leaky tube will flowinto'the pas sage in the floating channel and will pass back through the lowest tube, regardless of which tube is leaking. Y Uncertainty will also develop if the leak is in the tube sheet, eitherthrough the sheet or around a` tube,

in which event the leaking fluid will'flow down lthe face of the tube sheet and back through the lowermost tube in the passageway. It is the principal object of tliepresf entinvention, therefore, to provide meansA whereby external fluid pressure may be simultaneously applied torrall of the tubes in the nest, and any leaks which have de-v veloped fin thejtub'es will be directly indicated by fluid flowing from the respective tube. Y

The present invention -is particularly adapted for use in connection with heat exchangers provided with a tube nest having a floating head at one end, as disclosed, for example, in my copending application filed September 3, 1919, Serial No. 321,450, patented January 16, 1923 as Patent No.

1,442,7 83, and entitled Heat exchanger, theV invention contemplating the use of jigs or fixtures by which the space around the floating head of the tube sheet may be packed to permit the application of external fluid pressure to all of the tubes Within the shell, and to insure that the leaking fluid will drain out through the damaged tube.

The invention is illustrated by way of example in the accompanying drawing, in which the figure is a view in side elevation 7, 1923. Serial No.. 617,491.

showing a heat exchanger with parts broken for the sake of clearness, and disclosing the application of the present invention thereto.

'Referring more particularly to the drawing, indicates the shell of a heat ex changer, said shell being formed with body nozzles 11, said nozzles appearing arranged one above the other in the present drawing, but being designed to produce a circulation of fluid through the shell. 12 indicates a channel fitting adapted to be secured to the end of the shell adjacent the body nozzles. Thisfittiiig is provided with a pair of channel nozzles'13, which are shown as being positioned one above the other in the draw ing, but which permit a circulation of a fluid through tubes 14. It isV common practice to rigidly secure one tube sheet of the nest of tubes 14 between the end of the shell and the channel member A12. VThe opposite end of the tube nest is preferably free to float is fitted with a cap or oating head 15 indicated by dotted lines in the drawing. A body cover Y16 is secured over the end of the shell adjacent the floating head as indicated by dotted lines. The channel member 12 is normally closed at its outer end by a cap 17 indicated by dotted lines in the drawing.

The present invention is particularly concerned with means for sealing the end of the shell adjacent the floating tube sheet 24 and at the same timel to disclose the opposite ends of of the tubes.' This is done by supplying a` Vstuffing boxring of substantially 'the saine diameter as the shell, and indicated at 18. This ring has a bolting flange by which it may be clamped to the bolting J flange lof the shell and thus secured by bolts 19. Suitable packing gaskets 2O are interposed between the contiguousfaces of the ring and the shell, the gasket being preferably mounted in an annular face groove on the ring. The body portion of the 'ring` is cylindrical, its outer-end being counterbored to form a shoulder 21 against which a gasket ring22 may be seated. This ring will assume its normal position around the circumferential edge of the floating tube sheet 24. 'A stuffing gland 23 is adapted to project into the ring 18 and to be forced against the ring 22. The meeting faces of the stufling gland and the packing ring 22 are obliquely inclined so that pressure exerted against the ring will deform it and cause it to pack aroundthe circumferential edge of the tube sheet 24 and thus prevent leakage of fluid from within the shell. Plugs 25 are also provided to close the hole through which the bolts of floating head 15 pass. The gland 23 is held in its tightened position by bolts 26 which are fastened in the end face of the stufiing ring 18 and are threaded at their outer ends to receive nuts 27. Tube sheet supporting means are provided to steady the tube sheet 24twhen pressure is applied. This means comprises a screw 28 passing through a lug 29 carried by the gland 23. This screw is fitted with a swivel end 30 which rests against the face of the tube sheet 24.

in operation of the present invention the heat exchanger is prepared for testing by removing the cap 17 at one end of the structure and the shell cover 16 at the opposite end together with. the floating head 15. After this has been done ,the bolt holes in the floating tube sheet 24 are closed by plugs 25. The stui'nfmg ring 18 is then secured in position against the end face of the opened end of the shell by bolts 19 and a tight joint made by the use of the packing ring 2G. The rubber gasket 22 is -then disposed around the circumferential edge of the tube sheet 24 and is forced into a packing position vby the pressure of the gland 23 'as it is drawn against the ring by tightening the bolts 2G. Then the rubber ring 22 has formed a tight joint around the tube sheet the set screw 2S may be tightened to bring the end member 8O against the outer face of the 'tube sheet 2e and thus give it stability, at the saine time preventing the fluid pressure within the shell from loosening the joints between the tubes and the sheet. After the fixture has thus been applied to the heat exchanger or like structure7 fluid pressure may be Aestablished within the shell b` delivering a fluid under pressure througi the nozzles 11, and in view of the fact that the interior of the tubes will be under a condition of atmospheric pressure the uid from within the shell will readily leak through any holes or ruptures in any of the tubes. l/Vhen this takes place the fluid will drain out from one or the other end of the leaky tube. This may be instantly observed andthe respective tube replaced.

It will thus be seen that by the use of the testing fixtures here disclosed it is possible to accurately locate leaking tubes in a tube nest without removing the nest from its shell, and to permit-the tubes thus located to be readily replaced.

Vhile I have shown the preferred form of my invention as now known to me, it will be understood thatV various changes might be made in the combination, construction, and arrangement of parts by those skilled in the art7 without departing from the spirit of the invention, as claimed.

Having thus described my invention, what I claim and desire toV secure by Letters Patent is: Y

A method of testing the tube nest of a heat exchanger, which exchanger comprises an outer shell having a removable end, and within which shell the tube nest comprising tubes supported at one end in a tube sheet is disposed during the testing operation` said method consisting in first removing the end of the shell to disclose the tube sheet, thereafter applying means forming a joint for the opening between the tube sheet and thc shell wall and then creating a tight joint between said means and the-tube sheet and between the same and the wall of the shell, while permitting the open ends of the tubes projecting through the tube sheet to be disclosed, thereafter creatingrfluid pressure within the shell whereby said fluid will leak through the walls of the defective tubes, and thereafter drain from the disclosed ends of said defective tubes.

oARLr. BRAUN.v